Dating washburn bowlback mandlins
Most builders did not provide a full 12 sub-basses - here we see that Calamara has it now fully strung with sub-basses, unlike his previous specimen. It sure looks like an early precursor to the sloped shoulder design Bohmann would patent 15 years later (see final specimens below).
We don't know when he actually introduced the slope shoulders.
Shaeffer apparently granted license to both Bohmann and Lyon & Healy to build them, as evident from the label inside the Bohmann and this ad (graciously provided by Michael Holmes) depicting a seemingly identical instrument as a Washburn (L&H) brand.
The next two instruments are pictured in a rare Bohmann catalog from 1899, graciously shared by Bohmann collector and historian Rich Myers.
Ignoring contra bass for a moment (and readers know by now how I abhor that term), its important to note that Bohmann is calling it a harp guitar (Hansen was the first, in his 1891 patent).
There arent many people today comparing his guitars and mandolins directly against the Bohmann competitors of the period, especially the other Chicago firms, such as Lyon & Healy.
They were advertised as positively the largest guitar ever made.
With a width of 19 inches and body depth of six inches, this may not have been a false claim! As I read it, Calamara, also a mandolin teacher, is simply endorsing the company's mandolins, which he recommends to his students.
Hopefully, others with additional material and clues may discover this page and write in to share them.
The earliest harp guitar of Bohmanns is this unusual Form 4 instrument, with harp strings only on the body.
The first is claimed to be the first contra bass harp guitar made in America, built for the eminent Guitar Virtuoso, Sig. It is clearly a custom instrument, with a distinctive headstock and bridge.